Electric sparking device for gas-engines.



PATENTED FEB. 4, 1908.

E. R. MOFPITT. ELECTRIC SPARKING DEVICE FOR GAS ENGINES.

/V///Z u WIT/V5552? ATTORNEY UNITED STATES PATENT Ol li illjE.

EDWARD R. MOFFITT, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO IMPERIAL GAS ENGINE 00., OF SAN FRANCISCO, CALIFORNIA, A CORPORATION 01* CALIFORNIA.

ELECTRIC SPABKING DEVICE FOR GAS-ENGINES.

Specification of Letters Patent.

Patented Feb. 1, 1908.

Application filed March 13. 1907- Serial No. 382197- To all whom it may concern:

Be it known that I, EDWARD R. Morri'r'r, a citizen of the United States of America, resident of the city and county of San Francisco and State of California, have invented new and useful Improvements in Electric Sparking Devices for Gas-Engines, of which the following is a specification.

This invention relates to improvements made in devices for generating an electricspark in the cylinder of a gas-engine, to fire the charges of explosive mixture. Devices of this character generally comprise two electrodes in open circuit with a source of electricity and operated from some moving part of the engine in time with the movements of the piston, togencrate a spark between their contact-points or surfaces every time the two electrodes are caused to touch and separate. But being of necessity located in the explosion chamber, or in a compartment that communicates directly with the chamber in which the charge is exploded, the electrodes soon become carbonized or coated with the non-conducting matter deposited on their contact-surfaces, and are rendered uncertain or defective in operation; so that it is found necessary to clean the surfaces from time to time by removing the electrodes from the cylinder, or by opening the chamber or compartment in which they are inclosed, so as to give access to the contact-surfaces, that the operation of scraping or cleaning them may be carried on in the chamber.

The present invention has for its object to enable the contact-points or surfaces of elec trodes of this character to be readily cleaned of the deposits and restored to effective working condition without opening the chamber in which they are inclosed, and without removing them from the chamber; and to that end and purpose the invention. consists essentially in so forming or corn structingone of the electrodes that it movable by hand from the outside of the cylinder or the explosion chamber, and in addition to the motion imparted to it from the engine by which the spark generating surfaces are brought alternately in w'orking-contact and 'se'iarated, the contactsurfaces can be ru bed together or caused to scrape and brighten each other b the simple operation of moving one ofthe e ectrodes irom the outside of the cylinder.

The nature of the said invention and the manner in which I proceed to produce, apply and carry out the same will be explained at length in the following description, in which the accompanying drawings illustrating the application of my said invention to one type or cons truction of elec tric-sp arker are referred to by figures and letters.

Figure 1 of the drawing is a plan or topview of an electric sparker for a gas-engine embodying my invention, the device being of the type of electric-sparker composed of two electrodes, one of which is stationary, and the other is partially rotatable. Fig. 2 is a vertical sectionahview taken longitudinally through the center of the device, and showing a portion of the shell of the chamber or the cylinder in which it is inserted and fixed by screws. Fig. 3 is an end-elevation look ing from the right side of Fig. l and Fig. 4 is a similar elevation looking from the left side of Fig. l, but with the long coiled-spring omitted from the stem of the movable electrode.

These figures of the drawing illustrate the parts and features of the spark-generating device itself, but do not show the mechanism by which the electrodes are caused to make and break contact from a moving part of the engine.

The electrode a is the fixed or stationary contact. It is insulated from the surrounding metal of the plug or body I), by the bushing 0 of insulating material, and it is made the terminal of one pole of the generator from which current is su plied by means of a conducting wire a; attac red to the end outside. The other electrode. (1 is movable axially in its socket or hearing in the plug, and its movement on its axis is a partially rotating one, the extent of which is suliicient to bring its contact-piece or foot c against the routset-surface of the sintionary elec trode.

The foot 0 on the end of the stem (1 is held normally out of contact with the electrode a, and is separated from it after each contact by the torsional force of the coiled-spring g surrounding the stem. The movement that brings the two electrodes in contact to close, the circuit is effected by a partial rotation of the stem through the medium of a short arm or tappct h, on a.sleeve 7r loose on the stem, and the latter being movable on the sleeve 76 is also connected to it by the spring one end of which is secured to the stem d by I the spring 9 is not illustrated or described, for the reason that; electric sparking-devices ipeans of a collar or short sleeve m on the ead of the stem (1, while its opposite end is secured to the sleeve is. v

The tappet is the partthat'engages the camor'other part of the mechanism which,

by a rotary or oscillating motion, gives the required movement to the sleeve is, and through that part moves the stem (1 in the proper direction to bring the contact piece 6 against the opposite electrode a. g

The mechanical means for moving stem in opposition to thetorsional force of in which one electrdde is brought against the other by an oscillating or a partial rotary movement, are operated from some moving 'part of the engine in various ways, for example, by a cam, or a rocking-arm or lever acting against thetappet to move the stem against the force of the spring at the reuired intervals. The manner oioperating t e movable electrode is too well-known to those familiar with the art to require explanation.

A stop-pin p on the plug limits the throw of the tappet in one direction, and the end of the sleeve is locked to the end of the sleeve above it when the tappet is moved in the opposite direction, thereby giving artial rotation to the stem. The parts m are formed with projections or shoulders on their adjoining ends, that serve to lock one to the other in the forward throw of the tappet; and at the same time permit an adjustment axially of the stem by looseningthe uper sleeve or member and turning thefstem in it. For that purpose the sleeve is fastened on the stem (1 so as to be loosened and turned as occasion-may require, and in the present construction the parts are fastened y a pin-d inserted through the head of the upper member and the stem, as seen in Fig. 1.

In addition to the movement by which it is caused to make and break contact, as before described, the movable electrode is so fitted or adapted'that it can be moved longitudinally in the hole or socket in the plug, simply by grasping the head of the stem and giving it a short movement in. the direction of its longitudinal axis. This operation has the effect of cleanin the contact-surfaces of the two electrodes'by rubbing one against the I motion the;

, stasis electrode e in the required planejtoact against the contact-surface of the opposite electrode. This. spring 8 being compressed in the downward or inward thrust of the stem serves to r'eturn'or elevate that part when the pressure of the hand in working it is removed. The s ring ,8 surrounds the neck 15 through which the stem extends above-the face of 'theplug. The neck also forms a stop to arrest t e thrust of the stein. The reciprocating movement of the stem within the limits which are controlled in one direction by this stop and inthe opposite direction bya shoulder on the bottom of the stem, is of suflicient length or extent to bring the entire contact-surfaces that are in action on both electrodes in rubbing contact with each other to eifectively clean them.

Provision is made for changing theacting.

surface of the stationary electrode from time to time as it becomes burnedor worn, by using a in or contactiece of the well-known he ical shape as il ustrated at a" in Fig. 3. The pin a is fixed in lace by means of nuts '20 on the threaded ens of'the bushing on the outside of the plug. A fresh contact-surface on the pin a is presented to the .opposite electrode by loosening the nuts and turning the'pin in the bushing. I Asthus constructe and arranged for'operation,-it will be seen that the coacting surfaces Of'bOtll electrodes can be cleaned as often as desired without removing them from the engine, or o ening the chamber or compartment in Whic theyare'inclosed; also, that-the operation of cleaning the electrodes can be carried on from theoutside' of the chamber without disturbing the position or adjustment of the. arts or disconnecting the mechanism by w 'ch the" electrodes are actuated to make and break the circuit. A

In the present construction the artsare all mounted on or contained in t e plug,

which is secured in place on the shell of the eXpIlosion chamber by lag-screws 2 v aving thus described my invention, I claim 1. In an electric sparking device adapted for use in gas engines, the combination of a stationary electrode, a rotatable stem carryiece that constitutes the ing the contact movable electro e, a tapget piece loosely fitted on the stem so as to e rotatable relative thereto, a sleeve also loose upon the stem, the sleeve and tappet piece belng provided. with looking or mterengaging shoulders, arranged to permit a rotati've movement of one relative to the other, means for securing the sleeve fast to the stem in one or another position of rotative adjustment, and a spring connected at its opposite ends respectively with the tappet piece and the said sleeve, substantiall as set forth.

2. In an electric spar in -device for a gas engine, the combination 0 a plug, the stationary electrode therein, a' stem free to nected with the tappet-piece, and a coiled oscillate about its axis aad also movable lonspring interposed between the said tappet- 10 gitudinally in the plug" and carrying a conpiece and the plug, substantially as detact-piece on the end inside the explosionscribed for operation as set forth.

chamber of the engine a tappet-piece loosely EDWARD R. MOFFITT. fitted on the stem and rotatably movable Witnesses:

thereon, a coiled spring connected at one E. E. OSBORN,

end with the stem, 1ts other end being con- L. M. FRANK: 

